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2014 - Doctoral School n° 549
Health, Biological Sciences, & Life Chemistry
Thesis Proposal
1. Thesis Supervisor(s):
Name(s): KELLER Matthieu
Research Unit : Behavioral & Reproductive Physiology
Mail: [email protected]
2. Thesis Title : Puberty acceleration in females by exposure to male chemosignals.
3. Summary :
In mammals, it is well known that exposing females to male chemosignals from weaning
induces an early puberty onset and sexual maturation. In addition to these physiological
consequences, it also appears that this chemosensory exposition also leads to an earlier
expression of female sexual preferences. These effects have been well described in mice but
are also documented in farm animals. In this context, the project will be dedicated to test
whether these effects can be described in goats and used to reduce the improductive period
between weaning and the first reproductive experience.
The general experimental work will consist in 3 tasks:
1/ We will follow the sexual maturation of females goats exposed to sexually active males or
not from weaning. Sexual maturation will be followed by measuring the pulsatile release of
LH and progesterone levels at different time points from weaning. Sexual behavior will be
also measured during the first sexual encounter.
2/ Using the same experimental design, the degree of sexual maturation will be assessed by
neuroendocrine approaches measuring the development of neuropeptides involved in pubertal
transition (for example kisspeptin).
3/ In a final step, we will confirm the olfactory nature of these effects by stimulating females
with olfactory cues coming from males, such as urine or hairs. If successful, the identification
of the efficient chemosignal(s) and/or the brain responses to these chemosignals/odors will be
performed.
During this PhD, the candidate will be exposed to a variety of techniques and approaches
including animal behavior, endocrinology and neurobiology of pubertal transition, brain
imaging.
References:
Jouhanneau M., Cornilleau F. & Keller M. (2014). Peripubertal exposure to male odors stimulate female puberty
onset and sexual preference in adult mice. Hormones & Behavior, 65, 2, 128-133.
Jouhanneau M., Szymanski L., Martini M., Ella A. & Keller M. (2013). Kisspeptin : a new neuronal target of
primer pheromones in the control of reproductive function in mammals. General & Comparative Endocrinology,
188, 1, 3-8.